Looking at making a hardtop. Curious about the dimensions of those now in use. One material I could use is Durashield tongue and groove foam core panel. BUT it weighs a bit much. Total for the roof about 145 lbs, have to check this number. Thinking about dimension of about 12 ft by 7 t.

Terry, thanks, I'll look into this or maybe using foam core panel, might be able to get a one piece panel from the folks that make truck box panels. Don't have a n existing Bimini so that will need to be part of the project as well.
Marc

Hi, I wish I knew how to post pics. I built my hardtop from slightly less than 1/4" marine plywood over a welded aluminum tube frame. The joints are scarfed so that no seams are shown, and it becomes one solid sheet of plywood, then coated with 3 layers of epoxy, and polyurethane The finished top weighs about 80#. I used this for 2 years before selling "Here's 2 Life". The current owners are liveaboards and are currently in Puerto Rico. It looks like the top is holding up pretty well. I never had to do any maintenance on it before selling it.

I would give serious consideration to fitting plexiglass windows instead of clear vinyl. They will last much longer, give better visibility, and be easier to replace. I would if I were starting from scratch. I'm sure a smart hinging mechanism could be fitted to swing them out of the way on hot days.

Also consider rain gutters. If the water pours off it tends to splash everywhere. If there is some forward tilt, direct the water forward and down.

Thanks for all the ideas. I have used plexiglass on a boat project and found it surprisingly easy material. Made my own pilothouse windows. I've done foamglass frames but I'd like to keep this project simpler.